Heretofore, chip wringers have successfully been utilized to separate coolant/lubricating fluid from scrap material. A typical application occurs following a lathe or other machining operation in which helical metal chips of varying discrete length are formed. The scrap chips and coolant to be separated are collected and directed to a centrifugal chip wringer. As the material is centrifuged, it moves up a rotating bowl wall and passes over a screen having openings therein. The fluid separates from the scrap solid chips, and passes through the screen openings where it then is collected, often for reuse. The dried solid chips continue to pass over the screen and thereafter are blown to a collecting station.
While centrifugal chip wringers have been quite satisfactory for separating fluids from chip materials, the wringers unfortunately have not heretofore served to efficiently separate what is referred to as "swarf." Swarf is a slurry-like material generally generated in the course of a fine machining or grinding operation in which the scrap particles formed are quite fine as compared to the more discrete, finite-size chips generated, for example, in a lathe operation. Illustratively, in a grinding operation on steel stock, there is generated both a finished ground product as well as scrap product or swarf in which the swarf comprises (i) fine steel filings ground off the steel stock, (ii) fine pieces of metal or other material from the grinding tool, and (iii) lubricant/coolant. It has been found that in attempts to separate the coolant/lubricant from the swarf utilizing a conventional centrifugal chip wringer having a wedge wire screen, the swarf travels up the bowl wall of the centrifuge onto the screen wall. Unfortunately, it has been found that in most instances, the swarf material cannot be separated satisfactorily with a conventional screen known as a wedge wire screen in which a plurality of spaced members, such as illustrated in FIG. 2, are employed. It has been found that, after a relatively short period of time, the swarf plugs the screen openings such that either minimal separation occurs and/or the swarf solids pass through one or more screen openings with the fluid which also is undesirable. As a result, centrifugal separation of swarf has been an objective that has not heretofore been achieved with conventional centrifuge chip wringers having wedge wire screens.
What is desired is to utilize a centrifuge chip wringer that can successfully separate both chip and swarf materials. Further, it is desired to separate swarf material without excessive plugging of screen openings or having an excessive amount of the swarf solids passing through screen openings.